SEAL STRUCTURE FOR CIRCULAR TUBE BODY

摘要

In a sealing structure for a cylindrical body provided in a shell body, the occurrence of a defective seal caused by the straightness tolerance, roundness tolerance, and diameter tolerance of the cylindrical body can be prevented, and the sealing ability can be improved by absorbing the variations in straightness, roundness, and diameter even if the variations exist. A sealing structure for a cylindrical body 10 is configured so that an O-ring holder 13B in which a planar O-ring 12B that provides a seal in the planar direction and a radial O-ring 16B that provides a seal in the axial line direction of the cylindrical body 10 are incorporated in the crossing direction provided at both end parts of the cylindrical body 10; a pressing means 17B for pressing the O-ring holder 13B in the axial line direction of the cylindrical body 10 via a pressing lid 15B; the O-ring holder 13B is pressed against a tube sheet of the fluid chamber 20 via the pressing lid 15B by the pressing means 17B to press the planar O-ring 12B onto the tube sheet, whereby a fluidtight seal is provided between the fluid chamber 20 and the outside; and the radial O-ring 16B is pressed onto the outer periphery of the cylindrical body 10 to provide a fluidtight seal between the fluid passage 30 in the cylindrical body 10 and the fluid chamber 20.